The monitoring of electrical activity of electrical devices finds many useful applications in areas such as energy consumption, the building of user activity profiles, and in security or safety monitoring systems. For example, in a home environment, knowledge of the activity of electrical devices such as a washing machine, lighting devices, a cooker, a toaster or a coffee machine may provide useful information on household habits and user activity, enabling a profile to be built up.
A known solution for monitoring the activity of electrical devices employs a complex electrical meter system based on remote controlled modules plugged into power outlets and configured to measure the electrical consumption of the electrical equipment powered from the respective power outlet. Such, remote controlled modules are typically equipped with a wireless communication system based on low power wireless technology to remotely monitor and control the corresponding electrical appliance. Such advanced meter systems require however complex and expensive customized installation. Indeed, a recent research report on home automation and monitoring has indicated price and technical complexity as being the main market hurdles and inhibitors against widespread adoption. Another drawback of such techniques is that electrical devices may be moved from one power outlet to another power outlet. Moreover, some devices such as lighting devices are not always powered from a power outlet.
Other solutions for the detection of the activity of electrical devices are based on sensing their “EMI (electromagnetic interference) signature” by monitoring powerlines at one or several points of the power supply network. These techniques require however a customised calibration and training process to learn the EMI signature of various devices. Moreover, the EMI signatures may evolve with time. Complex signal processing techniques are required to disaggregate the signatures of the various active devices connected to the network and the obtained results are not always very accurate.
The present invention has been devised with the foregoing in mind.